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Python_Lecture13_Introduction to PyQt.pptx
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- 2. What is PyQt? Pythonbinding of the Qt toolkit Developed by Riverbank Computing Supports GUI development using C+ +-based Qt in Python PyQt is a bridge between Python and Qt
- 3. Why Use PyQt? Feature-richand flexible GUI toolkit Native look and feel across platforms Vast widget library and customization
- 4. PyQt Versions ■ PyQt4(legacy) ■ PyQt5 (widely used) ■ PyQt6 (modern, supports Qt6) ■ Compatibility and differences with Qt versions
- 5. Installing PyQt ■ Usingpip: `pip install PyQt5` ■ Qt Designer via `pyqt5-tools` ■ Optionally use conda environment
- 6. Your First PyQtApplication Minimal app example:
- 7. QApplication and QWidget QApplication managesthe control flow QWidget is the base class for all UI components All visual elements derive from QWidget
- 8. Layout Management ■ Ensures widgetsare placed and resized correctly Types: ■ QVBoxLayout, QHBoxLayout ■ QGridLayout, QFormLayout
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- 10. Signals and Slots Signals= events (e.g., button click) Slots = functions that handle events Automatic connection via `.connect()`
- 11. Connecting Signals toSlots ■ Slots can be regular functions or lambdas
- 12. Message Boxes DISPLAY MESSAGESWITH `QMESSAGEBOX` TYPES: INFORMATION, WARNING, CRITICAL, QUESTION
- 13. Menus and Toolbars Use `QMainWindow` formenu and toolbar support Actions defined via `QAction`
- 14. Dialogs and File Choosers ■Custom and built-in dialogs ■ Use `QFileDialog.getOpenFileName()`
- 15. Designer Tool ■ QtDesigner = drag-and-drop UI creation ■ Save as `.ui` files ■ Convert with `pyuic5`: – pyuic5 design.ui -o design.py
- 16. Custom Widgets andStyling ■ Subclass QWidget or other widgets ■ Override methods like `paintEvent()` ■ CSS-like styling using `setStyleSheet()` ■ button.setStyleSheet("background-color: lightgreen;")
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- 18. Set Up YourEnvironment 1. Install Python (>= 3.7) 2. Create a virtual environment 3. Install PyQt: `pip install PyQt5` 4. Optionally install pyqt5-tools for Qt Designer
- 19. Project Structure 1. main.py(entry point) 2. ui/ (for .ui files) 3. resources/ (images, icons) 4. widgets/ (custom widgets) 5. controllers/ (logic handlers)
- 20. Design UI withQt Designer ■ Use drag-and-drop interface ■ Save UI as .ui files ■ Convert with `pyuic5`: `pyuic5 main.ui -o main_ui.py` ■ Maintain separation of UI and logic
- 21. Create the MainApplication Use QApplication and main window: ```python import sys from PyQt5.QtWidgets import QApplication, QMainWindow app = QApplication(sys.argv) window = QMainWindow() window.show() sys.exit(app.exec_()) ```
- 22. Connect UI toLogic ■ Import the generated `main_ui.py` ■ Connect signals to custom slots (functions) ■ Example: ```python self.button.clicked.connect(self.handle_click) ```
- 23. Add Custom Widgets ■Subclass QWidget or other widgets ■ Override methods like `paintEvent()` ■ Integrate with main UI through layout
- 24. Style with QtStylesheets ■ Use `setStyleSheet()` with CSS-like syntax ■ Define themes and reusable styles Example: ```python self.setStyleSheet('QPushButton { color: white; background: blue; }') ```
- 25. Conclusion: - Keep UIand logic separate - Organize code into modules - Use signals/slots efficiently - Comment and document your code